This invention relates to material handling devices. More specifically, this invention is a material handling device that, among other components, includes an instrumented glove worn by an operator and measures the force the operator is imposing on an object and transmits the measured force in a manner to move the object.
Current material handling devices, e.g., U.S. Pat. Nos. 5,915,673 and 5,865,426 (Kazerooni), include a sensory end-effector held by a human operator, wherein the human operator force on the material handling device is then amplified electronically to drive the manual material handing device. The sensory end-effector that measures the human operator force is physically connected to the material handling device. A signal, representing the human force imposed on the end-effector by the human operator is measured by the force sensor in the end-effector and transmitted to a controller which controls the actuators of the material handling device. The controller causes the material handling device to move the end-effector and load appropriately so that only a pre-programmed small proportion of the load force is supported by the human operator and the remaining force is provided by the actuators of the material handling system.
Accordingly, the critical element of the cited prior art is the end-effector. The material handling device of the prior art responds only to the measured force from a force sensor in the end-effector. Thus, the material handling device is moved only by operator contact with the end-effector; it is not moved by operator contact with the load or any other part of the material handling device. The material handling device of this invention does not have any sensory end-effector and allows the operator to move the load by pushing onto any point on the load or onto any point on the material handling system itself. The material handling system of this invention includes an instrumented glove that is always worn by the operator and therefore remains with the operator. The instrumented glove of this invention generates a set of contact signals as a function of the contact force between the glove and the object being manipulated or the material handling device itself. A set of control signals representing the contact force is transmitted in the form of RF signals to a controller so that a command signal is generated. The command signal is sent to an actuator to provide the required assistance to maneuver the material handling device as a function of the force imposed by the operator, so that the operator provides only a small portion of the total force needed to maneuver the material handling device and the object being manipulated by the material handling device.
Instrumented glove is an important component of the invention described here. Currently, instrumented gloves are used in various applications. For instance, gloves with actuators that create forces on the fingers according to a set of computer instructions are designed to emulate forces on the wearer""s fingers and thumbs in telerobotics and virtual reality applications. U.S. Pat. No. 5,184,319 (Kramer) and U.S. Pat. No. 5,143,505 (Burdea et al.) are patents teaching examples of this application of instrumented gloves.
Another type of instrumented glove device includes sensors that measure kinematics type data (i.e., position, orientation, and posture) of the fingers, thumbs and wrists for various applications. Applications for gloves with embedded sensors measuring kinematics type data include for example: transforming human hand movements into electronic letters and characters, controlling the movement and actions of video characters, providing biofeedback for sports training such as tennis and golf, and assessing the mobility of human and/or animal joints. Examples of transforming human hand movements into electronic letters and characters are taught by, for example, U.S. Pat. No. 4,414,537 (Grimes) and U.S. Pat. Nos. 5,047,952 and 6,035,274 (Kramer et al.). Examples of controlling the movement and actions of video characters are found in the inventions taught by U.S. Pat. No. 5,796,354 (Cartabiano et al.) and U.S. Pat. No. 4,613,139 (Robinson II). U.S. Pat. No. 6,032,530 (Hock) teaches a method and an apparatus with sensors to measure body movement and flexure during kinetic activities. U.S. Pat. No. 4,542,291 (Zimmerman), teaches an optical flex sensor that can be used to detect bending of human movements. U.S. Pat. No. 4,715,235 (Fukui) teaches an electro conductive woven or knitted fabric, which changes its electrical characteristics when stretched and can be used as a switch. And finally, examples of assessing the mobility of human and/or animal joints are taught by, for example, U.S. Pat. No. 4,444,205 (Jackson) and U.S. Pat. No. 4,986,280 (Marcus et al.).
A third type of instrumented glove in the prior art includes glove devices with some sort of sensors to measure the interaction with other objects. Examples include the inventions taught by U.S. Pat. No. 5,581,484 (Prince) describing an apparatus for manually entering information into a computer by generating a virtual keyboard, mouse, graphics tablet or other forms of input data, and U.S. Pat. No. 4,055,905 (Budrose) describing a system that facilitates learning to type. Gloves with sensors to measure the interaction with other objects also include safety and sports training applications, such as taught by, for example, U.S. Pat. No. 6,016,103 (Leavitt) describing a glove to detect whether or not a motor vehicle driver is sleeping, and U.S. Pat. No. 5,669,809 (Townsend) describing a safety glove to be used in conjunction with a cutting machine, U.S. Pat. No. 5,681,993 (Heitman) and U.S. Pat. No. 4,488,726 (Murray) describing gloves for monitoring human gripping force on a golf club or on an aircraft control stick. Similarly, U.S. Pat. No. 6,126,572 (Smith) describes an apparatus for monitoring and displaying information related to pressure exerted at a point of interest during an isometric exercise, and U.S. Pat. No. 5,723,786 (Klapman) describes a boxing glove capable of measuring impact forces. And finally, U.S. Pat. Nos. 5,662,123, 5,449,002, 5,775,332 (Goldman et al.) and U.S. Pat. No. 6,033,370, (Reinbold et al.) describe capacitive sensor which has a plurality of layers forming a force detector which can be embedded in various patients"" shoe, boot, ankle, brace, crutch and handgrip to provide biofeedback to help patients relearn function or prevent atrophy.
Thus, prior to the present invention a need remained in the art for a simpler, more versatile device for maneuvering a manual material handling system that requires very little force from the operator and, wherein the operator directs the maneuvering of the material handling device to move an object, by pushing on any point on the material handling device or pushing on the object being maneuvered. Moreover, a system is also further needed to provide assistance for maneuvering the material handling device proportionally based on the force imposed by the operator, so that the operator provides only a small portion of the total force needed to maneuver the material handling device. Nevertheless, no prior art instrumented glove type device is designed for assisting manual material handling systems.
The present invention describes a material handling device for maneuvering at least one object, among other components, comprising: at least one actuator to cause the material handling device to move; an instrumented glove wearable by a human hand, wherein the instrumented glove detects a contact force imposed by the wearer on the object or a part of the material handling device and generates a set of contact signals representing the contact force; at least one transmitter circuitry capable of transmitting a set of control signals representing the contact signals to other locations; and a controller to receive and process the control signals and to generate command signals to control the actuator to cause the material handling device to move.
Additional objects, advantages and novel features of the invention will be set forth in part in the description and figures which follow, and in part will become apparent to those skilled in the art on examination of the following, or may be learned by practice of the invention.